U.S. Temperature and Precipitation Near-Normal in February

March 8, 2011

February 2011 was near normal for both temperature and precipitation averaged across the contiguous United States, according to the latest NOAA State of the Climate report issued today. The February average temperature was 34.0 F, which is 0.7 F below the long-term (1901–2000) average. Last month’s average precipitation was 1.81 inches, 0.21 inch below the same average. February marked the end of the meteorological winter (December–February), which featured below normal temperature and precipitation for the three-month period.

This monthly analysis, based on records dating back to 1895, is prepared by scientists at NOAA’s National Climatic Data Center in Asheville, N.C., and is part of the suite of climate services NOAA provides.

February temperature "statewide ranks" maps are available at the NCDC site.

During the first half of February, a southward-plunging polar jet stream held temperatures as much as 15 F below normal in much of the Central and Southern United States. Warm, tropical air advanced northward across these regions during the second half of the month, and temperatures reversed to nearly 15 F above normal. This flip-flop resulted in near normal temperatures for February.

Conditions were persistently warm throughout the entire month in the extreme Southeast, resulting in above normal averages for the region. Below average temperatures affected much of the western U.S.

Most of the Gulf and Atlantic Coast states experienced below average precipitation. It was the eighth driest February in Louisiana and Mississippi (tied with 1954).

Two severe weather outbreaks during the last week in February brought the month’s preliminary tornado count to 59. The final tornado count for February 2011 will rank among the 10 busiest Februaries on record.

It was the ninth driest January–February period on record for the contiguous United States. It was the second driest January–February in Virginia, fourth driest in New Mexico and seventh driest in North Carolina. Much of the west, south and southeast also had precipitation below the 20th century average.

Several record-breaking snowstorms resulted in above average snow cover extent. The “Groundhog Day Blizzard” dropped at least five inches of snow in 22 states. On Feb. 10, nearly two thirds of the contiguous U.S. was covered in snow and every state except Florida had snow on the ground.

Dry conditions across the Southern and Southeastern United States were associated with much-above average wildfire activity during February. Across the country, 8,226 wildfires burned approximately 187,000 acres — the most February wildfires during the 21st century and the second most acreage burned for any February.

February precipitation "statewide ranks" maps are available at the NCDC site.

The average winter temperature in the United States was 0.7 F below the 20th century average. Much of the lower than normal temperatures were confined to the regions east of the Rockies.

The majority of states, especially those east of the Rockies, were cooler than average during the winter. Maine and Nevada were the only two states with an average temperature that was above normal, while Georgia (3.9 F below normal) and Florida (3.7 F below normal) were much cooler than average.

Persistent dryness defined winter, especially in the South and Southeast climate regions where it was the third and ninth driest on record, respectively. The active weather pattern resulted in the eighth wettest winter season on record for the West North Central Climate Region.

A persistent high-pressure system in the Gulf of Mexico prevented moisture-laden systems from entering the southern regions. This resulted in several states having a winter period among their driest 10 percent on record. It was the third driest for Alabama, Louisiana, Mississippi and North Carolina.

Relentless precipitation in South Dakota and Montana resulted in their fourth and ninth wettest winter, respectively. It was the 11th wettest winter for North Dakota.

NCDC’s State of the Climate reports, which assess the current state of the climate, are released soon after the end of each month. These analyses are based on preliminary data, which are subject to revision. Additional quality control is applied to the data when latereports are received several weeks after the end of the month and as increased scientific methods improve NCDC’s processing algorithms.

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